[bpf-next,v4,0/4] Add prog_kfunc feature probe

Message

Tao Chen Feb. 6, 2025, 5:15 a.m. UTC

More and more kfunc functions are being added to the kernel.
Different prog types have different restrictions when using kfunc.
Therefore, prog_kfunc probe is added to check whether it is supported,
and the use of this api will be added to bpftool later.

Change list:
- v3 -> v4:
  - add fd_array init for kfunc in mod btf
  - add test case for kfunc in mod btf
  - refactor common part as prog load type check for
    libbpf_probe_bpf_{helper,kfunc}
- v3
  https://lore.kernel.org/bpf/[e-mail]

- v2 -> v3:
  - rename parameter off with btf_fd
  - extract the common part for libbpf_probe_bpf_{helper,kfunc}
- v2
  https://lore.kernel.org/bpf/[e-mail]

- v1 -> v2:
  - check unsupported prog type like probe_bpf_helper
  - add off parameter for module btf
  - check verifier info when kfunc id invalid
- v1
  https://lore.kernel.org/bpf/[e-mail]

Tao Chen (4):
  libbpf: Extract prog load type check from libbpf_probe_bpf_helper
  libbpf: Init fd_array when prog probe load
  libbpf: Add libbpf_probe_bpf_kfunc API
  selftests/bpf: Add libbpf_probe_bpf_kfunc API selftests

 tools/lib/bpf/libbpf.h                        |  18 ++-
 tools/lib/bpf/libbpf.map                      |   1 +
 tools/lib/bpf/libbpf_probes.c                 |  91 ++++++++++++--
 .../selftests/bpf/prog_tests/libbpf_probes.c  | 118 ++++++++++++++++++
 4 files changed, 214 insertions(+), 14 deletions(-)